{"id":2116,"date":"2017-08-10T10:56:06","date_gmt":"2017-08-10T02:56:06","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=2116"},"modified":"2026-08-18T12:09:38","modified_gmt":"2026-08-18T04:09:38","slug":"java%e6%9e%9a%e4%b8%be%e7%b1%bb%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=2116","title":{"rendered":"Java\u679a\u4e3e\u7c7b\u578b"},"content":{"rendered":"
\n

Java \u4ece JDK 1.5<\/strong> \u624d\u6709\u679a\u4e3e\uff0c\u548c\u6cdb\u578b\u4e00\u6837\u662f\u540e\u6765\u8865\u4e0a\u7684\u7279\u6027\u3002\u665a\u52a0\u7684\u8bed\u6cd5\u8981\u5411\u540e\u517c\u5bb9\uff0c\u7f16\u8bd1\u5668\u4f1a\u5e2e\u6e90\u7801\u505a\u5f88\u591a\u4e8b\uff08\u7c7b\u578b\u64e6\u9664\u3001\u6865\u63a5\u65b9\u6cd5\u3001foreach\u3001\u88c5\u7bb1\u62c6\u7bb1\uff09\uff0c\u672f\u8bed\u53eb\u8bed\u6cd5\u7cd6\u3002\u679a\u4e3e\u4e5f\u8d70\u8fd9\u6761\u8def\uff1a\u8868\u9762\u662f enum<\/code>\uff0c\u5e95\u4e0b\u662f java.lang.Enum<\/code> \u5b50\u7c7b\u3002<\/p>\n

1.5 \u589e\u52a0\u4e86\u62bd\u8c61\u7c7b java.lang.Enum<\/code> \u5f53\u6240\u6709\u679a\u4e3e\u7684\u57fa\u7c7b\uff0c\u5e76\u63d0\u4f9b EnumSet<\/code> \/ EnumMap<\/code>\u3002\u9879\u76ee\u91cc\u66f4\u63a8\u8350\u7528\u679a\u4e3e\u5e38\u91cf\uff0c\u800c\u4e0d\u662f\u63a5\u53e3\u5e38\u91cf\u6216\u7c7b\u5e38\u91cf\u3002<\/p>\n

\u4e00\u3001\u679a\u4e3e\u7c7b\u578b<\/h2>\n

\u65e5\u5e38\u5f00\u53d1\u5e38\u5b9a\u4e49\u5e38\u91cf\uff1b\u300aEffective Java\u300b\u5efa\u8bae\u7528\u679a\u4e3e\u66ff\u6362\uff0c\u53ef\u8bfb\u6027\u548c\u7ea6\u675f\u90fd\u66f4\u597d\u3002enum<\/code> \u9690\u542b\u7ee7\u627f Enum<\/code>\uff08\u62bd\u8c61\u7c7b\uff09\uff0c\u7b26\u5408 Class Enum<E><\/code> \u6a21\u5f0f\u3002\u6bcf\u4e2a\u679a\u4e3e\u503c\u90fd\u4f1a\u8fdb protected Enum(String name, int ordinal)<\/code>\uff1a\u540d\u5b57\u53d8\u6210\u5b57\u7b26\u4e32\uff0cordinal \u662f\u58f0\u660e\u987a\u5e8f\u3002<\/p>\n

public enum Week {\n\n    MON, TUE, WED, THU, FRI, SAT, SUN;\n\n}<\/code><\/pre>\n
\u4e0a\u9762\u5b9e\u9645\u76f8\u5f53\u4e8e\u8c03\u4e86 7 \u6b21\u6784\u9020\uff1aMON \u7684 ordinal \u662f 0\uff0cTUE \u662f 1\uff0c\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n\n\n\n\n\n\n\n\n\n
\u7528\u6cd5<\/th>\n\u505a\u4ec0\u4e48<\/th>\n<\/tr>\n<\/thead>\n
\u5e38\u91cf<\/td>\n\u628a\u76f8\u5173\u5e38\u91cf\u6536\u8fdb\u4e00\u4e2a\u7c7b\u578b\uff0c\u8fd8\u81ea\u5e26\u65b9\u6cd5<\/td>\n<\/tr>\n
switch<\/td>\n1.6 \u524d switch \u53ea\u652f\u6301 int\/char\/enum\uff0c\u53ef\u8bfb\u6027\u66f4\u597d<\/td>\n<\/tr>\n
\u52a0\u65b9\u6cd5<\/td>\n\u5b9e\u4f8b\u5217\u8868\u540e\u52a0\u5206\u53f7\uff0c\u4e14\u5fc5\u987b\u5148\u5199\u679a\u4e3e\u5b9e\u4f8b<\/td>\n<\/tr>\n
\u8986\u76d6 \/ \u63a5\u53e3 \/ \u7ec4\u7ec7<\/td>\n\u53ef toString\u3001\u5b9e\u73b0\u63a5\u53e3\u3001\u7528\u63a5\u53e3\u5206\u7ec4\uff1b\u4e0d\u80fd\u518d\u7ee7\u627f\u522b\u7684\u7c7b<\/td>\n<\/tr>\n
\u96c6\u5408<\/td>\nEnumSet<\/code> \u4e0d\u91cd\u590d\uff1bEnumMap<\/code> \u7684 key \u5fc5\u987b\u662f\u679a\u4e3e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u7528\u6cd5\u4e00\uff1a\u5e38\u91cf<\/h3>\n
1.5 \u4e4b\u524d\u53ea\u80fd public static final<\/code>\u3002\u73b0\u5728\u53ef\u4ee5\u628a\u4e00\u7ec4\u5e38\u91cf\u6536\u8fdb\u679a\u4e3e\uff1a<\/p>\n
public enum Color {\n\n  RED, GREEN, BLANK, YELLOW\n\n}<\/code><\/pre>\n
Color color = Color.RED;   \/\/color -> Red;<\/code><\/pre>\n
\u7528\u6cd5\u4e8c\uff1aswitch<\/h3>\n
enum Signal {\n\n        GREEN, YELLOW, RED\n\n    }\n\n    public class TrafficLight {\n\n        Signal color = Signal.RED;\n\n        public void change() {\n\n            switch (color) {\n\n            case RED:\n\n                color = Signal.GREEN;\n\n                break;\n\n            case YELLOW:\n\n                color = Signal.RED;\n\n                break;\n\n            case GREEN:\n\n                color = Signal.YELLOW;\n\n                break;\n\n            }\n\n        }\n\n    }<\/code><\/pre>\n
\u7528\u6cd5\u4e09\uff1a\u5411\u679a\u4e3e\u6dfb\u52a0\u65b9\u6cd5<\/h3>\n
\u81ea\u5b9a\u4e49\u65b9\u6cd5\u65f6\uff0c\u679a\u4e3e\u5b9e\u4f8b\u5217\u8868\u6700\u540e\u8981\u6709\u5206\u53f7\uff0c\u5e76\u4e14\u5b9e\u4f8b\u5fc5\u987b\u5199\u5728\u6700\u524d\u3002<\/p>\n
public enum Color {\n\n        RED(\"\u7ea2\u8272\", 1), GREEN(\"\u7eff\u8272\", 2), BLANK(\"\u767d\u8272\", 3), YELLO(\"\u9ec4\u8272\", 4);\n\n        \/\/ \u6210\u5458\u53d8\u91cf\n\n        private String name;\n\n        private int index;\n\n        \/\/ \u6784\u9020\u65b9\u6cd5\n\n        private Color(String name, int index) {\n\n            this.name = name;\n\n            this.index = index;\n\n        }\n\n        \/\/ \u666e\u901a\u65b9\u6cd5\n\n        public static String getName(int index) {\n\n            for (Color c : Color.values()) {\n\n                if (c.getIndex() == index) {\n\n                    return c.name;\n\n                }\n\n            }\n\n            return null;\n\n        }\n\n        \/\/ get set \u65b9\u6cd5\n\n        public String getName() {\n\n            return name;\n\n        }\n\n        public void setName(String name) {\n\n            this.name = name;\n\n        }\n\n        public int getIndex() {\n\n            return index;\n\n        }\n\n        public void setIndex(int index) {\n\n            this.index = index;\n\n        }\n\n    }<\/code><\/pre>\n
\u7528\u6cd5\u56db\uff1a\u8986\u76d6\u65b9\u6cd5<\/h3>\n
public class Test {\n\n    public enum Color {\n\n        RED(\"\u7ea2\u8272\", 1), GREEN(\"\u7eff\u8272\", 2), BLANK(\"\u767d\u8272\", 3), YELLO(\"\u9ec4\u8272\", 4);\n\n        \/\/ \u6210\u5458\u53d8\u91cf\n\n        private String name;\n\n        private int index;\n\n        \/\/ \u6784\u9020\u65b9\u6cd5\n\n        private Color(String name, int index) {\n\n            this.name = name;\n\n            this.index = index;\n\n        }\n\n        \/\/ \u8986\u76d6\u65b9\u6cd5\n\n        @Override\n\n        public String toString() {\n\n            return this.index + \"_\" + this.name;\n\n        }\n\n    }\n\n    public static void main(String[] args) {\n\n        System.out.println(Color.RED.toString());\n\n    }\n\n}<\/code><\/pre>\n
\u7528\u6cd5\u4e94\uff1a\u5b9e\u73b0\u63a5\u53e3<\/h3>\n
\u679a\u4e3e\u5df2\u7ecf\u7ee7\u627f Enum\uff0cJava \u53c8\u4e0d\u652f\u6301\u591a\u7ee7\u627f\uff0c\u6240\u4ee5\u4e0d\u80fd\u518d extends \u522b\u7684\u7c7b\uff0c\u4f46\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u3002<\/p>\n
public interface Behaviour {\n\n        void print();\n\n        String getInfo();\n\n    }\n\n    public enum Color implements Behaviour {\n\n        RED(\"\u7ea2\u8272\", 1), GREEN(\"\u7eff\u8272\", 2), BLANK(\"\u767d\u8272\", 3), YELLO(\"\u9ec4\u8272\", 4);\n\n        \/\/ \u6210\u5458\u53d8\u91cf\n\n        private String name;\n\n        private int index;\n\n        \/\/ \u6784\u9020\u65b9\u6cd5\n\n        private Color(String name, int index) {\n\n            this.name = name;\n\n            this.index = index;\n\n        }\n\n        \/\/ \u63a5\u53e3\u65b9\u6cd5\n\n        @Override\n\n        public String getInfo() {\n\n            return this.name;\n\n        }\n\n        \/\/ \u63a5\u53e3\u65b9\u6cd5\n\n        @Override\n\n        public void print() {\n\n            System.out.println(this.index + \":\" + this.name);\n\n        }\n\n    }<\/code><\/pre>\n
\u7528\u6cd5\u516d\uff1a\u7528\u63a5\u53e3\u7ec4\u7ec7\u679a\u4e3e<\/h3>\n
public interface Food {\n\n        enum Coffee implements Food {\n\n            BLACK_COFFEE, DECAF_COFFEE, LATTE, CAPPUCCINO\n\n        }\n\n        enum Dessert implements Food {\n\n            FRUIT, CAKE, GELATO\n\n        }\n\n    }<\/code><\/pre>\n
\u7528\u6cd5\u4e03\uff1aEnumSet \u4e0e EnumMap<\/h3>\n
\/**\n\n     *\n\n     * \u6f14\u793a\u679a\u4e3e\u7c7b\u578b\u7684\u904d\u5386\n\n     *\/\n\n    private static void testTraversalEnum() {\n\n        Light[] allLight = Light.values();\n\n        for (Light aLight : allLight) {\n\n            System.out.println(\"\u5f53\u524d\u706fname\uff1a\" + aLight.name());\n\n            System.out.println(\"\u5f53\u524d\u706fordinal\uff1a\" + aLight.ordinal());\n\n            System.out.println(\"\u5f53\u524d\u706f\uff1a\" + aLight);\n\n        }\n\n    }\n\n    \/**\n\n     *\n\n     * \u6f14\u793aEnumMap\u7684\u4f7f\u7528\uff0cEnumMap\u8ddfHashMap\u7684\u4f7f\u7528\u5dee\u4e0d\u591a\uff0c\u53ea\u4e0d\u8fc7key\u8981\u662f\u679a\u4e3e\u7c7b\u578b\n\n     *\/\n\n    private static void testEnumMap() {\n\n        \/\/ 1.\u6f14\u793a\u5b9a\u4e49EnumMap\u5bf9\u8c61\uff0cEnumMap\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u9700\u8981\u53c2\u6570\u4f20\u5165,\u9ed8\u8ba4\u662fkey\u7684\u7c7b\u7684\u7c7b\u578b\n\n        EnumMap<Light, String> currEnumMap = new EnumMap<Light, String>(\n\n        Light.class);\n\n        currEnumMap.put(Light.RED, \"\u7ea2\u706f\");\n\n        currEnumMap.put(Light.GREEN, \"\u7eff\u706f\");\n\n        currEnumMap.put(Light.YELLOW, \"\u9ec4\u706f\");\n\n        \/\/ 2.\u904d\u5386\u5bf9\u8c61\n\n        for (Light aLight : Light.values()) {\n\n            System.out.println(\"[key=\" + aLight.name() + \",value=\"\n\n            + currEnumMap.get(aLight) + \"]\");\n\n        }\n\n    }\n\n    \/**\n\n     *\n\n     * \u6f14\u793aEnumSet\u5982\u4f55\u4f7f\u7528\uff0cEnumSet\u662f\u4e00\u4e2a\u62bd\u8c61\u7c7b\uff0c\u83b7\u53d6\u4e00\u4e2a\u7c7b\u578b\u7684\u679a\u4e3e\u7c7b\u578b\u5185\u5bb9<BR\/>\n\n     *\n\n     * \u53ef\u4ee5\u4f7f\u7528allOf\u65b9\u6cd5\n\n     *\/\n\n    private static void testEnumSet() {\n\n        EnumSet<Light> currEnumSet = EnumSet.allOf(Light.class);\n\n        for (Light aLightSetElement : currEnumSet) {\n\n            System.out.println(\"\u5f53\u524dEnumSet\u4e2d\u6570\u636e\u4e3a\uff1a\" + aLightSetElement);\n\n        }\n\n    }\n\n}<\/code><\/pre>\n
\u66f4\u7ec6\u7684\u5b9e\u73b0\u539f\u7406\uff1ajava \u679a\u4e3e\u7c7b\u578b\u7684\u5b9e\u73b0\u539f\u7406<\/a>\u3002<\/p>\n
\n
\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a\u679a\u4e3e\u662f JDK 1.5 \u7684\u8bed\u6cd5\u7cd6\uff0c\u7f16\u8bd1\u540e\u4ecd\u662f Enum \u5b50\u7c7b\uff1b\u7528\u5b83\u6536\u62e2\u5e38\u91cf\u3001\u8fdb switch\u3001\u52a0\u65b9\u6cd5\u6216\u5b9e\u73b0\u63a5\u53e3\uff0c\u96c6\u5408\u4fa7\u4f18\u5148 EnumSet\/EnumMap\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
Java \u4ece JDK 1.5 \u624d\u6709\u679a\u4e3e\uff0c\u548c\u6cdb\u578b\u4e00\u6837\u662f\u540e\u6765\u8865\u4e0a\u7684\u7279\u6027\u3002\u665a\u52a0\u7684\u8bed\u6cd5\u8981\u5411\u540e\u517c\u5bb9\uff0c\u7f16\u8bd1\u5668\u4f1a\u5e2e\u6e90\u7801\u505a\u5f88\u591a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[15],"tags":[30],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2116"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2116"}],"version-history":[{"count":3,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2116\/revisions"}],"predecessor-version":[{"id":2269,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2116\/revisions\/2269"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}